hello,
there are a few issues around the implementation of helicopters that you could fly yourself. First, it would probably need another camera position/angle. If the camera would be locked so that moving the mouse wouldn't extend the view like it is the case when you are on the ground or maybe very slightly.
Secondly, how would the flying altitude being handled, always keeping the same altitude over the terrain shape under the helicopter? Or keeping the same distance to a collision model/terrain below the heli? Last option would cause some steep altitude bumps. Maybe a "fly heightmap" could be done so that it kind of interpolate those steep altitude changes but I am sure pasik would have some closer ideas about what *could* be doable.
Another, and probably the most problematic challenge would be to how would you fight against an hostile helicopter and with what? A portable auto-lock stinger rocket launcher could make sense (support item instead of LAW) and maybe some static stinger turret (like the TOW but for air vehicles). Anyway, I really don't see all of this to happen, at least not for RWR 1.0 as it would require too much code.
Here is an example of how it could look like (don't freak out, it's just a static model with offset inside the rwr world
)
For the submarine, imo the maps are just too small anyway. As for now the max water height is 2m, it would require some heightmap adjustments to make it not look too unrealistic. Also I wonder how you'd want to maneuvre as a submarine has a pretty high turning circle and fighting rubber boats with submarines is only something I could see happening in North-Korea